Caffeine as cancer-cell killer generates buzz

Toronto: Researchers have found novel ways of taking advantage of caffeine`s lethal effects on cancer cells - which they say could one day be used to advance cancer therapies for people.

Previous research has established that caffeine interferes with processes in cancer cells that control DNA repair, a finding that has generated interest in using the stimulant as a chemotherapy treatment.

However, given the toxic nature of caffeine at high doses, researchers from the University of Alberta opted to use it to identify genes and pathways responsible for DNA repair.

"The problem in using caffeine directly is that the levels you would need to completely inhibit the pathway involved in this DNA repair process would kill you," said Shelagh Campbell, co-principal investigator.

"We`ve come at it from a different angle to find ways to take advantage of this caffeine sensitivity," Campbell said.

Lead authors Ran Zhuo and Xiao Li, found that fruit flies with a mutant gene called melanoma antigen gene, or MAGE, appeared normal when fed a regular diet but died when fed food supplemented with caffeine.

The researchers found that the mutant flies` cells were super-sensitive to caffeine, with the drug triggering "cell suicide" called apoptosis. Flies fed the caffeine-laden diet developed grossly disfigured eyes.

Through this work, researchers identified three genes responsible for a multi-protein complex, called SMC5/SMC6/MAGE, which regulates DNA repair and the control of cell division.

Co-principal investigator Rachel Wevrick said that this finding is significant because it means that scientists one day could be able to take advantage of cancer-cell sensitivity to caffeine by developing targeted treatments for cancers with specific genetic changes.